I am working with the DRV8839 and have a few questions about implementation
- Would like to drive a brushed DC motor "single-ended" for rotation in one direction only (i.e. OUTx tied to one end of motor winding, other winding end to the current sense resistor then ground_ as shown on page 9 of the datasheet. Can the two OUTx lines be paralleled? That is, tired together at one end of the winding. Would also tie the two ENx lines together and the two INx lines, to ensure proper drive. The DRV8833 datasheet explicitily states that this can be done that part, but the 8839 makes no metnion of paralleling outputs.
- I assume that the recirculation current passes through the FET body diodes, do the part essentially always operates in Fast decay mode? Correct?
- Are the HS and LS FETs essentially identical? So the RDS(on) for HS alone would be ~1/2 of HS+LS?
- Why is there so much slope in the OCP limit? Practical designs will often hit the upstream supply current limit before the guaranteed max of 3.5A in the OCP, so it seems less than useful. This is a secondary concern because we plan to implement external low-side current sensing and can enforce a more predictable current limit from the MCU, but the OCP limit seems too wide to rely on?
- Does TI publish any additional design support info beyond the EVM documentation?
- This appears to be a new part (released early this year) so lifetime should not be an issue for a while. Does TI offer any lifetime guidance for this part?
Thanks